Nationals, Tigers swap right-handed relievers
Perry went 5-6 with two saves and a 4.07 ERA in 161 1-3 innings across 149 relief appearances over three seasons with Detroit. In 2011, he was 2-0 with a 5.35 ERA in 36 appearances for the Tigers, and 3-0 with a 3.03 ERA in 20 games at Triple-A Toledo. He was a first-round draft pick out of the University of Arizona in 2008.
Ryan was expendable because the Tigers reached an agreement on a one-year deal with Octavio Dotel.
Balester was 5-16 with a 5.17 ERA in 62 games - 40 in relief - from 2008-11 in Washington. Last season, he was 1-4 with a 4.54 ERA in 23 appearances for the Nationals, and 2-1 with a 4.35 ERA in 28 games at Triple-A Syracuse.
He was drafted in the fourth round in 2004 by the Montreal Expos, the franchise that moved to Washington in 2005.